The Bottom Line: 21st Century Shed-Less Plus Daily Supplement (Level 3) worked impressively well on my two Great Pyrenees dogs (extra long hair that constantly sheds). I could tell a difference within about four weeks of use. Less hair on the floor and my clothes, and healthier, shinier hair overall makes this product a winner. A bit high priced though. Quality of Ingredients This product is a great supplement because it contains loads of vitamins your pet may not get enough of through his or her regular food. I use Level 3, which is intended for older dogs and contains magnesium, Iron, Copper, Manganese, Zinc, Iodid, Vitamin A, Vitamin D, Vitamin E, Thiamine, Riboflavin, Niacin, Vitamin B12, Choline, and Vitamin C. It also contains essential fatty acids, such as omega-3, which is the key ingredient to support the reduction of shedding and skin and coat health. My female dog has pretty coarse hair ad within about 4 weeks of use, I could tell a great difference in the quality of her hair; it was less coarse, softer, and healthier looking overall. These tablets are also liver flavored, so my dogs love it and consider it a treat. Side Effects Side effects did occur in one of my dogs, but not the other one, so this will greatly depend on your pet's digestive sensitivity. My male dog started having really soft stool, which is unusual for him, but my female dog did not develop any reaction whatsoever. I use this supplements intermittently, and will do a 6-week cure, then stop for a couple of months, then do another cure. I find that it has worked best using it that way, versus all the time.